An OTT (Over The Top, over the Internet) refers to a service of providing a service based on the Internet. To be specific, a user obtains a service through broadband Internet access. Currently, an OTT on-demand service has contribute to the majority of network traffic.
With the increase of the number of OTT on-demand services, the prior art uses traffic grooming to reduce pressure that the traffic imposes on a bearer network. Considering that current OTT videos are mainly delivered by using a commercial CDN (Content Delivery Network, content delivery network) but the traffic and flow direction on the commercial CDN are beyond the control of an operator, the operator implements localization of OTT traffic by establishing a transparent cache system.
The transparent cache system caches media data replied by a server; when a request with respect to the content is received from a user subsequently, the corresponding content is obtained directly from the transparent cache system to reply to the user, without the need of requesting the content from the server providing a service, thereby saving network traffic from the transparent cache system to the server.
As shown in FIG. 1, a user terminal 1 (end user 1) requests media data from an OTT server, and the request is forwarded to the server through an intermediate network device (service POP), where the network device has an embedded transparent cache system; when a request is received subsequently, the network device redirects a request packet with respect to the OTT server to the embedded transparent cache system; after finding that the content requested by the user terminal 1 is unavailable locally, the transparent cache system sends a request packet to the OTT server and sends a media data reply provided by the OTT server to the user terminal 1; after the packet of the same content requested by a user terminal 2 (end user 2) from the OTT server is redirected by the network device to the transparent cache system, the transparent cache system replies to the user terminal 2 (end user 2) directly by using cached content.
Because the access transaction of a user terminal may be terminated by the transparent cache system and cannot reach the OTT server, an OTT service provider cannot count media data access of the user terminal, for example, access times, access time, and the like. In addition, because the access request of the user terminal is directly replied by the transparent cache system and the corresponding access request cannot reach the OTT server, the OTT service provider cannot control access content and the transparent cache system also suffers the security risk of attack caused by masses of requests.